Switch construction



Dec. 15, 1959 J. J. MIKOS 2,917,608

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SWITCH CONSTRUCTION Application July 31, 1957, Serial No. 675,426 12 Claims. (Cl. 200-146) This invention relates, generally, to disconnecting switches for high voltage application and it has particular relation to switches arranged to be opened by a load current interrupting tool or auxiliary circuit interrupter while they are carrying load current. A disconnecting switch ordinarily includes a switch blade that is pivoted on one line terminal and swings into and out of engagement with a switch tongue on another line terminal. Provision is made for locking the switch blade in closed position. A pull ring carried by a latch lever may be pivoted on the switch blade at the swinging end beyond the switch tongue for operating a latch to permit opening of the switch blade. When the switch blade is opened by a load interrupter tool or auxiliary circuit interrupter, it is desirable that little or no part of its opening stroke be used for unlatching the switch blade since the latter should be moved to a position where there is no likelihood of flashover after the circuit has been interrupted by the tool or auxiliary circuit interrupter. A substantial movement of the pull ring to unlatch the switch blade is required and such operation preferably is performed by manipulation of the toolor auxiliary circuit interrupter. This invention is directed particularly to providing a solution to this problem.

Among the objects of this invention are: To provide for opening a disconnecting switch of the type shown in US. Patent No. 2,351,826, issued June 20, 1944, modified as illustrated in US. Patent No. 2,621,272, issued December 9, 1952, by means of a load interrupter tool or auxiliary circuit interrupter constructed as disclosed in application Serial No. 569,909, filed March 6, 1956, now Patent No. 2,816,981, issued December 17, 1957, when the load interrupter devices of the first and second mentioned patents are removed; to shunt the stationary contact and switch blade and unlock the latter from the former without requiring relative movement apart of the terminals of the load interrupter tool which permits unlocking of the switch blade and movement thereof away from the stationary contact before there is any movement apart of the terminals of the load interrupter tool; to limit the movement of the anchor member to initial and final positions; to bias the anchor member to the initial position; to maintain proper air gap distance between parts of the disconnecting switch and of the load interrupter tool which are energized at different voltages after the circuit has been interrupted by the tool and while it is being disengaged in order to prevent restriking of the arc; to latch the anchor member in the final position where it facilitates the detachment of the previously attached terminal of the load interrupter tool in order to accomplish the immediately preceding object; to restore the anchor member to the initial position as an incident to the movement of the switch blade to the closed position; and to accommodate the load interrupter tool on either side of the disconnecting switch.

Other objects of this invention will, in part, be obvious and in part appear hereinafter.

United States Patent This invention is disclosed in the embodiment thereof shown in the accompanying drawings and it comprises the features of construction, combination of elements and arrangement of parts that will be exemplified by the construction hereinafter set forth and the scope of the application of which will be indicated in the appended claims.

For a more complete understanding of the nature and scope of this invention reference can be had to the following detailed description, taken together with the accompanying drawings, in which:

Figure l is a view, in side elevation, of a disconnecting switch in which the present invention is embodied and showing the application thereto of a load interrupter tool the details of which are disclosed in application Serial No. 569,909, filed March 6, 1956;

Figure 2 is a view, in side elevation, and at an enlarged scale of the upper portion of the disconnecting switch shown in Figure 1, the load interrupter tool being in the fully closed position;

Figure 3 is a view, at an enlarged scale, in front elevation of the upper end of the disconnecting switch shown in Figure 1;

Figure 4 is a view, similar to Figure 3, and in addition showing in perspecfi' e the application of the load interrupter tool;

Figure 5 is a view, in side elevation, of the upper disconnecting switch terminal and switch blade, the latter being moved toward the open position and the load interrupter tool being extended to a position where it is ready to trip and open the circuit; and

Figure 6 is a view, similar to Figure 5, but showing the load interrupter tool in the full open position at which time the circuit has been opened thereby without arcing externally.

Referring now particularly to Figures 1, 2 and 3 of the drawings it will be observed that the reference character 10 designates, generally, a disconnecting switch of the general type disclosed in US. Patent Nos. 2,351,826 and 2,621,272. It includes a channel base 11 which carries upper and lower line insulators 12 and 13. While the channel base 11 is shown in a vertical position, it will be understood that it can be located in an underhung position, if desired. The insulators 12 and 13 carry upper and lower line terminals 14 and 15 each of which includes a terminal pad 16 and 17 to permit connection of circuit conductors as is readily understood. Extending outwardly from the upper line terminal 14 is a switch tongue 18 while a fulcrum member 19 extends outwardly from the lower line terminal 15. A switch blade, shown generally at 20, is pivoted at 21 on the fulcrum member 19. As shown in Figure 3, the switch blade 20 includes blade members 22 and 23 which are spaced apart throughout the major portions of their length. At their upper ends they converge and carry downwardly extending auxiliary blade members 24 and 25 which engage opposite sides of the switch tongue 18 when the switch blade 20 is in the switch closed position. The auxiliary blade members 24 and 25 are biased into contact engagement with the switch tongue 18 by means of springs 26 and 27 which surround a bolt 28 that extends not only through the blade members 24 and 25 but also through the converging upper ends of the blade members 22 and 23.

It is desirable to lock the switch blade 20 in the closed position. For this purpose the two-way'lock mechanism shown in Patent No. 2,351,826 can be used. The application of this lock mechanism to the disconnecting switch 10 is illustrated more clearly in Figure 2 of the drawings. As there shown a notch 31 is provided in the upper side of the switch tongue 18 for receiving the lower end of a latch bolt 32. The latch bolt 32 is slidably mounted between the auxiliary blade members 24 and 25. It is provided with a slot 33 near its lower end through which a guide pin 34, carried by the auxiliary blade members 24 and 25, extends. The latch bolt 32 is biased downwardly by-a coil compression spring 35 which reacts against a bolt 36 which extends through the upper ends of the auxiliary blade members 24 and 25 and also through the upper ends of the blade members 22 and 23. Rockably mounted on the bolt 36 is a latch lever 37 the lower end of which is bifurcated as indicated at 38. These bifurcated end portions 38 have arcuate slots 39 which receive pins 40 that are carried by the blade members 22 and 23 and auxiliary blade members 24 and 25. Shoulders 41 on the latch lever 37 underlie the lateral sides of a head portion 42 which is integral with the latch bolt 32. At the upper end of the latch lever 37 is an integrally formed eye 43 for receiv ing a prong of a switch stick. It will be understood that the latch lever 37 can be rocked about the bolt 36 in one direction or the other and when such rocking movement occurs one or the other of the shoulders 41 engages the corresponding side of the head portion 42 and moves the latch bolt 32 upwardly against the biasing force of the spring 35 to a position sufficient to remove the lower end from the notch 31. On opening movement, this permits the switch blade 20 to be swung to the open position and on closing movement this permits the lower end of the latch bolt 32 to clear the upper edge of the switch tongue 18 and permit the switch blade 20 to be moved to the fully closed position.

Also formed integrally with the upper line terminal 14 is a socket member 46. As described in Patent No. 2,621,272 the socket member 46 is arranged to removably receive a load interrupter device which is intended to be stationarily mounted on and become a part of the disconnecting switch 10. When such a load interrupting device is employed, it is operated automatically by movement of the switch blade 20 to the open position to effect the final opening and initial closing of the circuit, thereby avoiding arcing externally between the switch blade 20 and the switch tongue 18. In some applications the expense involved in the use of the load interrupter device permanently attached to the disconnecting switch is unwarranted. Accordingly, instead of employing it the load interrupter tool or auxiliary circuit interrupter of the type shown in application Serial No. 569,909, filed March 6, 1956, can be employed.

The load interrupter tool or auxiliary circuit interrupter is shown, generally, at 47 and only a general description thereof will be set forth herein. It will be noted that the load interrupter tool 47 is mounted on a live line insulating stick 48 of the type ordinarily found in a linemans truck and adapted to have various types of live line tools clamped thereto. At its upper end the live line stick 48 is provided with a metallic fitting 49 for detachable connection to a metallic strut 50. Near its upper end the strut 50 is provided with a laterally extending prong 51 which is arranged to engage the eye or pull ring 43 that is carried by the upper end of the latch lever 37. A keeper 52 cooperates with the prong 51 to prevent it from slipping out of the eye 43. Movable with the strut 50 and prong 51 is an inner insulating sleeve 53 which moves within an outer insulating sleeve 54 for the purpose of cocking a spring operated mechanism to effect the separation of contact members within the load interrupter tool 47 in such manner as to interrupt the current fiow within it without external arcing and without the formation of an are between the switch blade and the switch tongue 18 when the former is moved away from the latter. Near its upper end the outer insulating sleeve 54 carries a conducting part including a bow contact member 55 which is arranged to be placed over and connected and anchored to a hook shaped end 56 of an anchor member 57.

In order to permit operation of the switch blade 20 from either side, two anchor members 57 are employed,

one positioned on each side of the upper line terminal 14 and extending generally alongside of opposite sides of the upper end of the switch blade 20.

It will be recalled that some rocking movement of the latch lever 37 is required in order to lift the latch bolt 32 out of locking engagement with the notch 31. During this initial operation and while the latch lever 37 is being moved to unlock the latch bolt 32, it is undesirable that any relative movement take place between the inner insulating sleeve 53 and the outer insulating sleeve 54 of the load interrupter tool- 47. The reason for this is that there must be a minimum relative movement between these sleeves 53 and 54 in order to cock the spring in the load interrupter tool 47 in order to effect opening of the contacts therein and it is undesirable to use any of this relative movement merely for rocking the latch lever 37. When it is recalled that line voltage is impressed between the upper line terminal 14 and the switch blade 20 when the latter is moved toward the open position and the circuit has been interrupted by the load interrupter tool .7, it will be appreciated that there is a minimum distance that must be maintained under these conditions in order to prevent restriking of the arc.

Accordingly, it is desirable that some movement of the anchor member 57 be permitted while the latch lever 37 is being rocked to unlatch the latch bolt 32. This is accomplished through the interaction between the prong 51 and the eye 43. Also it is desirable that there be some movement of the switch blade 20 away from the switch tongue 13 before there is any relative movement between the sleeves 53 and 54 to effect cooking of the spring within the load interrupter tool 47 In order to permit such movement, each anchor member 57 is provided with a stub shaft 58 which is rockably mounted on a support bracket 59 that may be formed integrally with the upper line terminal 14 on opposite sides of the switch tongue 18. In order to bias the anchor members 57 to the initial positions shown in Figures l and 2 of the drawings coil springs 60 are provided around the stub shafts 58. One end 61 is attached to the respective stub shaft 58 while the other end 62 extends over the respective support bracket 59.

As the lineman pulls on the live line stick 4S and with it the load interrupter tool 47, the anchor member 57 to which the bow contact member 55 is applied rocks outwardly until a stop pin 63, carried by the respective support bracket 59 is engaged by a nose portion 64 which constitutes a downwardly and rearwardly extending part of the anchor member 57. Another stop pin 65 is engaged by each anchor member 57 in the initial position, the latter being held against the former by the respective coil spring 60.

It is desirable to hold the anchor members 57 in the final position with the nose portion 64 in engagement with the stop pin 63 in order to permit the removal of the bow contact member 55 from the hook shaped end 56 while maintaining the established open gap between the upper line terminal 14 and the switch blade 20. For this purpose latch means including a spring pressed ball 66 is employed. Each spring pressed ball 66 is positioned at the outer end of a socket 67 located in the respective support bracket 59. A spring 68 in each socket 67 urges the respective ball 66 outwardly for engagement with the extreme lower end of the nose portion 64 of the respective anchor member 57.

In order to swing the anchor members 57 from the final positions back to the initial positions and overcome the holding effect of the latch means includng the spring pressed ball 66, detents 69 are provided on each of the anchor members 57 as shown more clearly in Figure 3. These detents extend inwardly from the anchor members 57 and the outer ends thereof are located in the path of movement of the latch lever 37 As the switch blade 20 is swung toward the switch closed position one or the other of the detents 69 is engaged to shift the respective nose portion 64 past the respective spring pressed ball 66. The anchor member 57 then is operated back to the initial position by its spring 60.

It will be understood that the particular form of disconnecting switch 10 shown and described herein is for illustrative purposes and that other forms of disconnecting switch can be employed or modified as may be desired.

In describing the operation of the load interrupter tool 47 for opening the disconnecting switch 10, it will be assumed that the latter is in the closed postion, as shown in Figures 1 and 2 of the drawings and that the lineman is positioned to the left of the switch 10. The load interrupter tool 47 then is applied to the hook shaped end 56 of the anchor member 57 on the right hand side of the upper line terminal 14 as shown in F.gure 4 of the drawings. Further, it will be assumed that there is no load interrupter device in the socket member 46. As a result, reliance is placed on the'load interrupter tool 47 for effecting the final circuit interruption w.thout the creation of an external are between the switch blade 20 and the switch tongue 18 or other part of the upper line terminal 14.

The lineman exerts a pull on the live line stick 48 after he has placed the bow contact member 55 over the hook shaped end 56 of the right hand anchor member 57 and has inserted the prong 51 into the eye 43. The force required to overcome the tension of the rght hand coil spring 60 is less than the tension of the spring in the load interrupter tool 47 with the result that, as the live line stick 48 is moved generally outwardly and to the left of the disconnecting switch 10, the inner and outer insulating sleeves 53 and 54 move conjointly and the latch lever 37 rocks about the bolt 36 to shift the latch bolt 32 out of the slot 31. While this is taking place the right hand anchor member 57 is rocking forwardly. The movement continues and, after the latch bolt 32 is withdrawn from the notch 31, the switch blade 20 is moved away from the switch tongue 18.

The movement continues until the nose portion 64 of the right hand anchor member 57 depresses the spr'ng pressed ball 66 and comes to rest against the stop pin 63. This relationship is illustrated in Figure 5. Here the spring pressed ball 66 acts to latch the anchor member 57 in the extended position against the stop member 63 and against the biasing force of the spring 60.

Since the anchor member 57 cannot rock any further to the right, the bow contact member 55 and outer insulating sleeve 54 of the load interrupter tool 47 are prevented from moving further while the inner insulating sleeve 53 moves conjointly with the live line stick 48 to cock the spring within the load interrupter tool 47. During such operation the switch blade 20 is moved to the position shown in Figure 5 where the circuit is maintained solely through the load interrupter tool 47 and the switch blade 20 is positioned far enough away from any energized part of the upper line terminal 14 to prevent restriking of the arc therebetween once the circuit is interrupted by the load interrupter tool 47.

A slight further movement of the live line stick 48 causes the spring inside of the load interrupter tool 47 to be tripped and the contacts thereof to be opened. The full extent of opening movement is illustrated in Figure 6. Here the switch blade 20 is positioned well beyond any location where the arc might be restruck either externally of the load interrupter tool 47 or internally thereof. Since the anchor member 57 is held in the displaced position, the live lfne stick 48 can be moved in a reverse direction suiiiciently to lift the bow contact member 55 oil? of the hook shaped end 56. Then the opening movement of the switch blade 26 can be continued with the-prong 51 swinging the switch blade 24 downwardly through the required extent, such as through 90 or 180 as may be desired.

The load interrupter tool 47 is detached from the eye 43 by rocking it about its longitudinal axis. This swings the keeper 52 out of locking position and permits the prong 51 to be withdrawn from the eye 43.

When the switch blade 20 is swung to the switch closed position, the latch lever 37 engages the detent 69 of the anchor member 57 which has previously been operated and forcibly moves it past the spring pressed ball 66. The continued movement of the latch lever 37 and switch blade 20 to the closed posit on or the force exerted by the spring 60 restores the anchor member 57 to the init a1 position where the disconnecting switch 10 is ready for another opening operation in the manner previously described.

Since certain changes can be made in the foregoing construction and different embodiments of the invention can be made without departing from the spirit and scope thereof, it is intended that all matter shown in the accompanying drawings and described hereinbefore shall be interpreted as illustrative and not in a limiting sense.

What is claimed as new is:

1. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever movably mounted on said switch blade and provided with a pull ring, latch means interposed between said latch lever and said other terminal for holding said switch blade closed and operable to unlatched position on application of a pull to said pull ring to swing said switch blade to open position, an anchor member movably mounted on said other terminal for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, and means preventing further movement of said anchor member by said one terminal of said load interrupter tool after said anchor member has been moved thereby through a predetermined extent to permit unlatching of said latch means by said latch lever as a result of simultaneous movement of said other terminal of said load interrupter tool.

2. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever movably mounted on said switch blade and provided with a pull ring, latch means interposed between said latch lever and said other terminal for holding said switch blade closed and operable to unlatched position on application of a pull to said pull ring to swing said switch blade to open position, an anchor member movably mounted on said other terminal for receiving one terminal of a load interrupter too-l while the other terminal thereof engages said pull ring, stop means on said other terminal cooperating with said anchor member to limit the movement thereof between initial and final positions, and spring means biasing said anchor member to said initial position.

3. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever movably mounted on said switch blade and provided with a pull ring, latch means interposed between said latch lever and said other terminal for holding said switch blade closed and operable to unlatched position on application of a pull to said pull ring to swing said switch blade to .open position, an anchor member movably mounted on said other terminal for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said other terminal cooperating with said anchor member to limit the movement thereof between initial and final positions, spring means biasing said anchor member to said initial position, and means for holding said anchor member in the final position against the action of said spring means to facilitate detachment of said one terminal of said load interrupter therefrom.

4. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever movably mounted on said switch blade and provided with a pull ring, latch means interposed between said latch lever and said other terminal for holding said switch blade closed and operable to unlatched position on application of a pull to said pull ring to swing said switch blade to open position, an anchor member movably mounted on said other terminal for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said other terminal cooperating with said anchor member to limit the movement thereof between initial and final positions, spring means biasing said anchor member to said initial position, and means responsive to the closing movement of said switch blade for restoring said anchor member to its initial position.

5. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever rockably mounted at the swinging end of said switch blade and constituting an endwise extension thereof and having a pull ring at its outer end, a latch bolt carried by said switch blade and interposed between said latch lever and said contact member for holding said switch blade closed and operable to unlatched position on application of a pull to said pull ring to swing said switch blade to open position, a support bracket extending outwardly from said other terminal to one side of the swinging end of said switch blade, an anchor member rockably mounted on said support bracket and extending generally alongside said switch blade in closed position and away from the blade pivot and having means at its outer end for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, and means preventing further rocking of said anchor member by said one terminal of said load interrupter tool after said anchor member has been swung thereby through a predetermined extent to permit unlatching of said latch bolt by said latch lever as a result of simultaneous movement of said other terminal of said load interrupter tool.

6. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever rockably mounted at the swinging end of said switch blade and constituting an endwise extension thereof and having a pull ring at its outer end, a latch bolt carried by said switch blade and interposed between said latch lever and said contact member for holding said switch blade closed and operable to unlatched position on application of a pull to said pull ring to swing said switch blade to open position, a support bracket extending outwardly from said other terminal to one side of the swinging end of said switch blade, an anchor member rockably mounted on said support bracket and extending generally alongside said switch blade in closed position and away from the blade pivot and having means at its outer end for receiving one terminal of a load interrupter tool while .the other terminal thereof engages said pull ring, stop means on said support bracket cooperating with said anchor member to limit the movement thereof between initial and final positions, and spring means reacting between said support bracket and said anchor member to bias the latter to said initial position.

7. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced relation with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever rockably mounted at the swinging end of said switch blade and constituting an endwise extension thereof and having a pull ring at its outer end, a latch bolt carried by said switch blade and interposed between said latch lever and said contact member for holding said switch blade closed and operable to unlatched position, a support bracket extending outwardly from said other terminal to one side of the swinging end of said switch blade, an anchor member rockably mounted on said support bracket and extending generally alongside said switch blade in closed position and away from the blade pivot and having means at its outer end for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said support bracket cooperating with said anchor member to limit the movement thereof between initial and final positions, spring means reacting between said support bracket and said anchor member to bias the latter to said initial position, and latch means carried by said support bracket and cooperating with said anchor member for holding it in the final position against the action of said spring means to facilitate detachment of said one terminal of said load interrupter tool therefrom.

8. A disconnecting switch comprising, in combination, a pair of line terminals mounted in insulated spaced rela tion with a hinge member carried by one terminal and a contact member carried by the other terminal, a switch blade pivoted to said hinge member for movement into and out of engagement with said contact member, a latch lever rockably mounted at the swinging end of'said switch blade and constituting an endwise extension thereof and having a pull ring at its outer end, a latch bolt carried by said switch blade and interposed between said latch lever and said contact member for holding said switch blade closed and operable to unlatched position, a support bracket extending outwardly from said other terminal to one side of the swinging end of said switch blade, an anchor member rockably mounted on said support bracket and extending generally alongside said switch blade in closed position and away from the blade pivot and having means at its outer end for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said support bracket cooperating with said anchor member to limit the movement thereof between initial and final positions, spring means reacting between said support bracket and said anchor member to bias the latter to said initial position, latch means carried by said support bracket and cooperating with said anchor member for holding it in the final position against the action of said spring means to facilitate detachment of said one terminal of said load interrupter tool therefrom, and a detent carried by said anchor member and extending into the path of closing movement of said latch lever for restoring said anchor member to its initial position.

9. Switch means comprising, in combination, relatively stationary and movable switch members for opening and closing an electrical circuit, a latch lever movably mounted on said movable switch member and provided with a pull ring, latch means interposed between said latch lever and said stationary switch member for holding said switch members closed and operable to unlatched position on application of a pull to said pull ring to move said movable switch member to open position, an anchor member movably mounted on said stationary switch member for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, and means preventing further movement of said anchor member by said one terminal of said load interrupter tool after said anchor member has been moved thereby through a predetermined extent to permit unlatching of said latch means by said latch lever as a result of simultaneous movement of said other terminal of said load interrupter tool.

10. Switch means comprising, in combination, relatively stationary and movable switch members for opening and closing an electrical circuit, a latch lever movably mounted on said movable switch member and provided with a pull ring, latch means interposed between said latch lever and said stationary switch member for holding said switch members closed and operable to unlatched position on application of a pull to said pull ring to move said movable switch member to open position, an anchor member movably mounted on said stationary switch member for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said stationary switch member cooperating with said anchor member to limit the movement thereof between initial and final positions, and spring means biasing said anchor member to said initial position.

11. Switch means comprising, in combination, relatively stationary and movable switch members for opening and closing an electrical circuit, a latch lever movably mounted on said movable switch member and provided with a pull ring, latch means interposed between said latch lever and said stationary switch member for holding said switch members closed and operable to unlatched position on application of a pull to said pull ring to move said movable switch member to open position, an anchor member movably mounted on said stationary switch member for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said stationary switch member cooperating with said anchor member to limit the movement thereof between initial and final positions, spring means biasing said anchor member to said initial position, and means for holding said anchor member in the final position against the action of said spring means to facilitate detachment of said one terminal therefrom.

12. Switch means comprising, in combination, relatively stationary and movable switch members for opening and closing an electrical circuit, a latch lever movably mounted on said movable switch member and pro vided with a pull ring, latch means interposed between said latch lever and said stationary switch member for holding said switch members closed and operable to unlatched position on application of a pull to said pull ring to move said movable switch member to open position, an anchor member movably mounted on said stationary switch member for receiving one terminal of a load interrupter tool while the other terminal thereof engages said pull ring, stop means on said stationary switch member cooperating with said anchor member to limit the movement thereof between initial and final positions, spring means biasing said anchor member to said initial position, means for holding said anchor member in the final position aganst the action of said spring means to facilitate detachment of said one terminal therefrom, and means responsive to the closing movement of said movable switch member for restoring said anchor member to its initial position.

References Cited in the file of this patent UNITED STATES PATENTS 1,856,313 Brennan May 3, 1932 2,498,250 Cole Feb. 21, 1950 2,671,145 Lindell Mar. 2, 1954 

